Electric lock

ABSTRACT

A lock which includes a bolt which is movable between a locked position and an unlocked position against the action of a biassing element such as a spring, first retaining element which is engaged with the bolt and which retains the bolt in the locked position and which is movable between a first position at which the first retaining element restrains the bolt from being moved from the locked position to the unlocked position and a second position at which the first retaining element restrains the bolt from being moved from the unlocked position to the locked position, remotely actuable release element, which when actuated, causes movement of the first retaining element from the first position to the second position, and handle element for moving the bolt from the locked position to the unlocked position when the first retaining element is disengaged from the bolt.

BACKGROUND OF THE INVENTION

This invention relates to a lock which is suitable for use as a doorlock. It is to be understood however that the scope of the invention isnot confined to this particular application.

A door lock which is in widespread use has a bolt which is movablebetween locked and unlocked positions. The bolt is movable by means of akey which is manually rotatable and which acts on one or more locklevers which have formations which match complementary formations on thekey. A catch, which forms part of the lock, is movable by means of ahandle so that a door, to which the lock is mounted, can be moved from aclosed position to an opened position.

Electrically operated locks have been proposed wherein the movement ofthe bolt is effected by means an electrical device such as a solenoid ormotor. The solenoid is actuated by means of a security mechanism such asa keypad and draws power from a mains or battery supply in order to movethe bolt.

The provision of power to a lock of this type may pose some problems.

Firstly if use is made of power drawn from a mains supply then one isfaced with the difficulty of leading electrical conductors to the lock.On the other hand if use is made of an onboard power supply such as oneor more batteries then the current drain on the batteries may be suchthat the batteries must be replaced at regular intervals of relativelyshort duration. This problem becomes pronounced under certain conditionsfor example when friction forces are generated, which impede themovement of the lock components.

SUMMARY OF THE INVENTION

The invention provides a lock which includes a bolt which is movablebetween a locked position and an unlocked position, first retainingmeans which is engaged with the bolt and which retains the bolt in thelocked position, remotely actuable release means for moving the firstretaining means out of engagement with the bolt, and handle means formoving the bolt from the locked position to the unlocked position whenthe first retaining means is disengaged from the bolt.

The bolt is movable from the locked position to the unlocked positionagainst the action of a biassing element such as a spring. Energyaccumulated in the biassing element may be used for subsequentlyreturning the bolt to the locked position. This eliminates the need foran external energy source to operate the lock; for example electricalenergy required to drive an electric motor to move the bolt. The handleis operated by a person opening the door. Thus the energy to bias thebiassing element is supplied by the user.

Preferably the first retaining means is movable between a first positionat which the first retaining means restrains the bolt from being movedfrom the locked position to the unlocked position and a second positionat which the first retaining means restrains the bolt from being movedfrom the unlocked position to the locked position, and the releasemeans, when actuated, causes movement of the first retaining means fromthe first position to the second position.

The lock may include biassing means which is biassed when the bolt ismoved to the unlocked position. The biassing means may provide energyfor restoring the bolt to the locked position.

The release means may be electrically actuable. The release means maytake on any suitable form and for example may include an electric motor.

The release means may be responsive to a signal which is output by areceiver and decoder unit which, in turn, is responsive to an externallygenerated signal for causing operation of the lock.

Preferably the lock includes energy storage means which accumulatesenergy as the bolt is moved to the unlocked position, second retainingmeans, engageable with the bolt, for retaining the bolt in the unlockedposition, and means for disengaging the second retaining means from thebolt whereupon the energy storage means causes the bolt to be moved tothe locked position.

The first and second retaining means may be formed by inter-engageableformations respectively on the bolt and on at least one lever.

The first retaining means may be movable in any appropriate way and, forexample, use may be made of a cam, a gear mechanism e.g. a worm geararrangement, which acts on the cam, and an electrical motor which drivesthe gear mechanism, and hence the cam, in a controlled manner.

The first and the second retaining means may also be movable by means ofa key of any appropriate type. This enables the bolt to be manuallylocked or unlocked according to requirement.

The lock may include a receiver and decoder which receives an externallygenerated signal from any appropriate source such as a card reader,keypad, any suitable recognition device, a switch device, a radiotransmitter or the like. The scope of the invention is not limited inthis regard. If a correctly encoded signal or a valid signal is receivedthen the retaining means may be moved in the manner described.

Communication with the lock may be unidirectional, or bidirectional e.g.in a “challenge-response” routine or mode. In each case a signal may betransmitted, by a direct link or a wireless link, from a source which isclose to a lock, or from a remote source e.g. a central control point.The signal could simultaneously actuate a number of locks. A phone link,an Internet connection, or any similar device or arrangement could beused to address the lock directly or through the medium of a controlunit. The lock may be capable of reporting or responding, e.g. to acontrol unit or any actuating source, through any appropriate medium,directly or through a wireless, Internet or other link. The lock may forexample report to an alarm system to indicate that a door is open orclosed or, possibly, that the door has been forced open.

Where a plurality of locks are used, a central system or an alarm systemmay be installed that can individually or collectively instruct thelocks to lock and unlock. The locks may report to the central systemindicating information such as whether they have been successfullylocked, and whether the respective doors are open or closed. The centralsystem may also communicate with other systems which may include garagedoors to lock and unlock such doors and to check on their status such asopen or closed. The central system may be interfaced by a user directlyor may be communicated with by the user via a telephone link, theInternet or a satellite. This communication may take place via a varietyof mediums, such as wired, radio frequency and infrared links.

Single hand held controllers may be used to lock a variety of locks withone button press, or single locks with the press of another button, or acode of button presses. For certain buttons of the hand held controller,the power that is emitted may be higher than for other buttons of thesame hand held controller. This makes it possible to limit the workingrange of some of the buttons on the hand held controller and helps toprevent the accidental locking and unlocking of surrounding locks if aspecific lock is to be locked and unlocked, if a hand held controllercan lock and unlock more than one lock. For hand held controllerscommunication can take place via a variety of mediums, such as radiofrequency and infrared links.

It is also possible to actuate the lock by means of any appropriatedevice, e.g. a push button, which is installed at a convenient and safelocation and which may be linked directly to the lock.

The lock may include an energy storage device such as at least onebattery. The battery may be stored in a housing in which mechanicalcomponents of the lock are mounted or in a separate easily accessiblehousing.

The lock may include cam means which acts on the first retaining means,an electrically driven gear mechanism, which is remotely controllable,for causing controlled movement of the first retaining means from thesaid first position to the said second position, energy storage meanswhich accumulates energy as the bolt is moved, and means for preventingmovement of the cam means at least in one direction when the bolt ismoved to the unlocked position.

The energy storage means may provide energy for restoring the bolt tothe locked position. Alternatively, if energy is stored when the bolt ismoved to the locked position, the energy storage means is used torestore the bolt to the unlocked position.

The electrically driven gear mechanism may include an electric motorwhich drives a gear arrangement such as a worm gear and preferably isresponsive to a signal which is output by a receiver and decoder unitwhich, in turn, is responsive to an externally generated signal forcausing operation of the mechanism.

The first retaining means may include at least one lever which isengageable with a stop formation on the bolt.

A sensor of any appropriate type e.g. optical, magnetic, inductive etc.may detect whether a door, to which the lock is fitted, is open orclosed and only allow actuation of the bolt in a manner which depends onthe door position, e.g. to move the bolt to a locked position only whenthe door is closed.

The lever or levers may be actuated manually, for example directly bymeans of a key which acts on the lever or levers, or indirectly by meansof a key which acts on a cylinder which, in turn, acts on lever orlevers, or in any other way.

Preferably the lock includes a device which is movable between a firstposition at which, upon operation of the handle, the bolt is caused tomove to the unlocked position, and a second position at which, uponoperation of the handle, no movement of the bolt results. The saiddevice may for example be a spring or a catch.

The invention also provides a method of operating a lock which includesat least a locking bolt, the method including the steps of storingenergy when the bolt is moved manually in a first direction, latchingthe bolt at a first position using retaining means, transmitting asignal to actuate the retaining means to unlatch the bolt, and allowingthe locking means to move in a second direction opposite the firstdirection under the action of the stored energy.

The transmitted signal may be transmitted from a remote point using anelectronic key eg, suitable wireless means, or a connection which ismade directly to the retaining means or an actuator thereof.

It fails within the scope of the invention to actuate the lockelectronically or by means of a mechanical key. By making use of atransmitter which can transmit more than one signal it is possible tocontrol the operation of the lock in a variety of ways, according torequirement. For example the operation or potential operation of amechanical key can be disabled electronically to enhance the security ofthe lock. Thus, by way of example, the aforementioned cam means mayinclude a cam surface which actuates one or more members which preventdirect or indirect engagement of a mechanical key with the bolt or witha device which causes bolt movement.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is further described by way of examples with reference tothe accompanying drawings in which:

FIG. 1 illustrates a lock according to a first form of the invention ina locked configuration,

FIG. 2 shows the lock of FIG. 1 in a locked, but ready to open,configuration,

FIG. 3 shows the lock of FIG. 1 in a completely unlocked position,

FIG. 4 shows the lock latched, but not locked,

FIG. 5 illustrates on an enlarged scale an arm which is used in the lockof the invention,

FIGS. 6 to 10 respectively illustrate different stages of operation of alock according to a second form of the invention,

FIG. 11 illustrates a lock according to a third form of the invention ina locked configuration,

FIG. 12 shows the lock of FIG. 11 in a locked, but ready to open,configuration,

FIG. 13 shows the lock of FIG. 11 with a bolt in an unlocked positionbut with a handle cam, which is used to move the bolt, in an operativeposition,

FIG. 14 is a view similar to FIG. 13 but with the handle cam in aninoperative position,

FIG. 15 illustrates a modified lock according to the invention,

FIG. 16 schematically depicts certain electronic components used forcontrolling the operation of the lock of the invention,

FIG. 17 shows another embodiment of a lock according to the inventionwhich is operated using a solenoid,

FIG. 18 is an enlarged view of a complex controlling cam used in thelock of FIG. 17, and

FIGS. 19 and 20 are respective flow chart representations of operationsfor unlocking and locking the lock of FIG. 17.

DESCRIPTION OF PREFERRED EMBODIMENTS

FIGS. 1 to 4 of the accompanying drawings illustrate a lock 10 accordingto a first form of the invention from the side in different operatingconfigurations which are described hereinafter.

The lock is intended for mounting in a door or any other closure. Thedoor is however not shown in the drawings for it plays no part in theinvention. The lock is designed to be used as a replacement for aconventional lever lock but this aspect is given merely by way ofexample and it is to be understood that the principles of the inventionare not restricted in any way.

The lock 10 includes a housing 12 with a face plate 14. The housing 12is intended to be located in a hollow formed in a side edge of a door,not shown. The face plate is normally located in a recess formed in theside edge of the door.

The housing is formed from two halves which are engageable with eachother to form enclosure for the various components of the lock. Thedrawings illustrate the lock with one half of the housing removed sothat the components are visible.

A handle cam 16 is mounted to a shaft or axle 18 which extends from thehousing 12. Two handles 20 are fixed to opposed projecting ends of theshaft, in a conventional manner. Only one handle 20 is shown, in dottedoutline, in the drawings.

A bolt 22 is mounted for sliding movement relatively to the housing, asis indicated by means of a double-headed arrow. The bolt passes througha slot 24 in the face plate and includes an elongate slot 26 which isengaged with a pivot and guide pin 28 which projects from the housing.

At its innermost end 30 the bolt has a downwardly facing recessedformation 32. A bolt catch or stop formation 34 extends from the bolt.

One or more lock levers 36 which are substantially of a conventionaldesign are mounted for pivotal movement on the pin 28. Each lever has ashaped aperture 38. An arm 40 extends upwardly from the levers. The armis formed from a resilient material and is shown on an enlarged scale onFIG. 5, and is further described hereinafter. A spring 42 acts on thelevers.

A keyhole 44 is formed in the housing slightly below the levers 36.

A lever 46, referred to as a power lever, is mounted for pivotalmovement about a point 48. A shaped spring 50 is fixed to the bolt at apoint 52, and has a hook formation 54 which is adjacent a spigot orsimilar formation 60 on the power lever 46. When the spring 50 is in theposition shown in FIG. 1 the lock formation 54 is out of reach of thespigot 60 and cannot engage with the spigot.

A spring 62 acts between the bolt 22 and the housing or the face plate14.

A worm gear drive 64, is mounted above the bolt and its output shaft isfixed to a cam 66 which is mounted for rotation about an axis 68. Asmall electric motor 70 is used to rotate the worm gear drive, and hencecause controlled movement of the cam.

In FIG. 1 the cam 66 is in an inoperative position and opposes an upperend surface 72 of the arm 40 (see FIG. 5).

The bolt 22 has an outwardly extending ramp surface 74 positionedslightly lower than the end surface 72, when the lock is in the FIG. 1mode.

A micro-controller 76 which includes a receiver and decoder unit ismounted inside the housing. This unit draws power from a battery 78which is mounted inside the housing and which powers the motor 70.

The micro-controller 76 and the battery 78 may, according torequirement, be mounted in an enclosure (not shown) which is separatefrom the housing 12 and which is relatively easily accessible.

The lock has a catch or latch 82 biased to a latching position by meansof a spring 84, and is acted on via a link 86, by an upper cam 88 whichis rotatable by the handle 20 against the biasing action of a spring 90.

FIG. 1 illustrates the lock in a locked position with the bolt 22 andthe catch 82 extending from the housing. If the lock is installed in adoor then clearly the bolt 22, in the illustrated position, isengageable with a striker plate on a door frame in order to keep thedoor in a closed and locked position.

The lock may be unlocked with a key which is inserted into the keyhole44, in a conventional manner. If the key is rotated then formations onthe key engage with complementary formations in the recessed formations32 on the levers and lift the levers, which pivot about the pin 28. Inthis way the levers are moved out of engagement with the formation 34and, as the key is further rotated, the key engages directly with asurface on the bolt and moves it to the right. The bolt is able to moveto the right for the catch formation 34 then has a position, relativelyto the apertures 38, as is shown in FIG. 2. The handle 20 can be rotatedto move the catch 82 to a retracted position, as shown in FIG. 3, andthe door can be opened. If the bolt is still engaged with the strikeplate, as shown in FIG. 1, operation of the handle will only causemovement of the catch, and it will not be possible to open the door. Ifthe handle is released the catch goes to the position shown in FIG. 4 tokeep the door in a latched position. The door, if open, could also beclosed with the catch then moving to allow closure. The working of thelock of the invention, in this regard, is substantially conventional andhence is not further elaborated on herein. It is to be noted howeverthat the manual unlocking of the lock takes place without actuating thereceiver and decoder unit 76.

At this point the lock can be locked manually, by using a key, orelectronically. If the lock is to be locked manually then the key isengaged with the key hole and rotated in the locking direction. Thelevers 36 are lifted and the formations on the key engage with therecessed formations 32 on the levers moving the bolt to the left. Thespring 62 contracts assisting bolt movement.

On the other hand the lock can be operated remotely in any appropriateway eg. electronically, by pressing a lock button on a remote controldevice such as a radio transmitter or use made of a keypad which, ifcorrectly operated, generates a signal which is transmitted to thereceiver by means of a conductor on wirelessly, in any suitable way. Thetransmitted signal is received and identified by the receiver anddecoder unit 76 and, if acceptable, the motor 70 is actuated thereby todrive the worm gear drive 64. The cam 66 is rotated in a clockwisedirection about the axis 68 and the arm 40 is moved downwardly as thecam strikes the upper surface 72 of the arm. As the arm pivotsdownwardly the levers 36 are pivoted upwardly and the apertures 38 aredisengaged from the stop formation 34. The spring 62, which accumulatedenergy when the bolt was moved to the unlocked position, now releasesits stored energy and consequently under the action of the restoringforce of the spring 62 the bolt is moved to the locked position.

The use of a radio transmitter, for controlling the operation of thelock, is given merely by way of example and any suitable remote ornon-contact method can be used for actuating the lock. An actuator ofthis type may more generally be referred to as an electronic key. Theelectronic key ideally has the facility for making use of a coded signalwhich is decoded by the unit 76 to enable lock operation to take place.If an incorrectly encoded signal is received then the lock will not beoperated. Clearly this is a security feature.

If the receiver recognises a transmitted code then referring again toFIG. 1, when the bolt is in a locked position the motor 70 is drivenwith power drawn, for this purpose, from the battery 78. The motordrives the cam in a clockwise direction into engagement with the uppersurface of the arm which, in turn, is moved downwardly, pivoting thelevers upwardly, against the biasing action of the spring 42, as isshown in FIG. 2. As the levers move, the shaped apertures are moved outof engagement with the stop formation 34. An end of the spring 50, whichextends to the right in the drawing, is moved upwardly by the leversfrom the relaxed position shown in FIG. 1, to an operative position,shown in FIGS. 2 and 3, the hook formation 54 is moved to a position atwhich it can engage with the spigot 60.

If the handle is depressed before the cam is engaged with the levers 36and the spring 50, the spring 50 yields to the spigot 60 when the handleis released, and the spigot 60 is then able to engage with the hookformation 54, as per normal operation.

At this stage, if the handle 20 is rotated, the power lever 46, rotatingabout the pivot point 48, is moved so that the spigot 60 engages withthe hook formation 54 of the spring 50. The spring 50 is moved to theright and the bolt 22 is thereby also moved to the right, relatively tothe housing, extending the spring 62, to the FIG. 3 position. Duringthis process the catch 82 is also withdrawn and consequently the doorcan be opened.

As the bolt moves to the right the ramp formation 74 slides under theupper end of the arm 40 which is now more or less in line with the rampformation and the ramp urges the upper end of the arm away from the boltout of engagement with the cam 66. When the arm disengages from the camthe levers 36 are immediately pivoted in a clockwise-direction about thepoint 28 by the spring 42 and take up the position shown in FIGS. 3 and4 at which the formation 34 is again engaged with the apertures 38thereby retaining the bolt in the withdrawn or unlocked position. Thecatch 82 can then be moved to an extended or retracted position, asrequired, simply by moving the handle 20, substantially in aconventional way, without effecting the position of the bolt.

If the bolt is to be unlocked then, as already pointed out, this can bedone electrically or mechanically, according to requirement, in therespective manner which has already been described.

The operation of the lock can be summarised as follows:

1. movement of the bolt to the unlocked position takes place manuallyand, in the process, energy is stored in the spring 62;

2. energy for moving the bolt to the locked position, particularly ifuse is made of a remote actuator such as a keypad or transmitter, isprovided by the spring 62 which accumulates energy when the bolt ismoved to the unlocked position;

3. the bolt can be unlocked manually by means of a key, or electricallyby causing the cam 66 to disengage the lever apertures 38 from theformation 34;

4. as the bolt is moved from the locked to the unlocked position theramp formation 74 causes the arm 40 to disengage from the cam 66. Theworm gear 64 has a gear ratio which is stepped down substantially fromthe motor 70 to the cam. In the opposite direction, from the cam to themotor, the gear ratio is stepped up. Consequently any attempt to rotatethe cam 66 directly and not via the motor, will be ineffective and causedamage to the cam or to the worm gear. The ramp formation thereforecauses disengagement of the cam from the arm when the possibility existsof the cam being moved manually;

5. the use of a key with the bolt in the unlocked position causes thelock levers 36 to pivot upwardly against the biasing action of thespring 42 and the formation 34 is thereby disengaged from the apertures38. As noted the bolt moves to the locked position under the action ofthe key and the spring 62;

6. with the bolt in the withdrawn position shown in FIG. 4 the cam mustbe rotated so that it is moved from the illustrated position at which itis partly under the upper end of the arm 40 to a position at which itagain bears on the upper surface 72 of the arm. The arm is then forceddownwardly to pivot the lock levers upwardly so that the formation 34 isdisengaged from the apertures 38. In this instance the spring 62, alone,exerts force on the bolt to move it to the locked position;

7. with the bolt in the position shown in FIG. 4 the handle 20 can bemoved freely to move the catch 82 in or out, in a conventional manner,and no interaction with the bolt takes place. When the bolt has beenreleased, as is illustrated in FIG. 2, the handle 20 can also be movedfreely but in this instance the bolt and the catch 82 are moved inunison. In the FIG. 1 position however the bolt is prevented from movingby the engagement of the formation 34 with the apertures 38 in the locklevers. If an attempt is made to rotate the handle 20 then the spigot 60will not engage with hook formation 54, since the whole spring 50 is inits relaxed position, and in this relaxed position the hook is out ofreach of the spigot 60. When the cam is engaged as shown in FIG. 2, thespigot 60 will engage with the hook formation 54 when the handle isoperated. A situation may however arise where the bolt will not be ableto move freely, such as a skew door that places a force on the bolt.Damage to the assembly can therefore arise if excessive force is exertedon the handle. Any appropriate technique may be adopted to reduce thelikelihood of damage arising in this way. A suitable approach is toconnect the handle 20 to the axle 18 using a clutch type device which iscapable of transmitting limited force only. The force is in excess ofthat which is required to move the bolt from the locked to the unlockedposition. If the bolt is restrained from moving in this way then, oncethe force level is exceeded, the clutch mechanism slips and the handleis moved downwardly without transmitting excessive force to the bolt.

FIGS. 6 to 10 illustrate a second embodiment of the invention. Whereapplicable reference numerals which are the same as the referencenumerals used in the embodiment of FIGS. 1 to 4 are used in FIGS. 6 to10 to indicate like components. The following description is confinedessentially to differences in the forms of construction.

The spring 42 is dispensed with. The shaped spring 50 is supplemented bya leaf spring 100. The levers 36 include cam formations 102 and,optionally, an additional leaf spring 104.

It is apparent that the motor which is used in the lock of the inventionis extremely small to enable it to fit in the available space inside thehousing 12. The motor is also small so that power consumption isreduced. This has the natural consequence that the motor has relativelylow torque.

The motor drives the motor cam via a gearbox and the motor cam drivesthe arm 40.

In the FIG. 1 embodiment the spring 42 acts permanently on the levers,resiliently connecting the levers to the housing. Thus a fairlysignificant load is at all times transferred to the arm 40 and the cam66 must work against this force when it is rotated. This results in anincrease in power consumption. It is therefore desirable to reduce theforce against which the cam 66 must operate during action of the cam onthe arm.

The embodiment shown in FIGS. 6 to 10 is designed to reduce powerconsumption but, at the same time, provide spring loading on the levers36, when required.

The leaf spring 100 forces the levers 36 downwardly but with moderatepressure. More force is required when the levers must be returned to theunlocked position shown in FIG. 8. At this time the leaf spring 100bears against cam formations 102 on the levers exerting a larger forceon the levers which urges the levers to return to the unlockedpositions. The leaf spring 100 only engages with the cam formations 102when the bolt has been retracted to a position which is beyond aretracted normal, unlocked position at which the bolt no longer exerts alocking function. The bolt is able to move slightly beyond the retractedposition by a further amount, when the handle 20 is fully turned, andthen returns to the normal unlocked position when force on the handle isreleased.

When the bolt 22 is returned to its normal unlocked position, the leafspring 100 is no longer in contact with the cam formations 102 and arelatively low force is again applied to the levers 36 via the leafspring 100. This is important for, as has been noted, when relativelylow force is applied to the arm 40 the cam 66 can be turnedcomparatively easily and pivot the arm, and hence the levers, when thebolt is to be restored to the locked position.

Use may also be made of the additional leaf spring 104 which is fixed tothe levers 36 and placed so that the catch formation 34 on the bolt 22can engage with the spring 104 under certain circumstances. The springonly exerts a force on the levers 36 when the bolt has been moved beyondthe normally unlocked position to a fully retracted position by fullyrotating the handle 20.

When the catch formation 34 abuts the spring 104, see FIG. 8, anadditional force is exerted on the levers 36 urging the levers to pivotdownwardly to a locked position.

It is to be noted that the formation 34 only acts on the spring 104, andhence on the levers 36, when the bolt 22 has been moved beyond itsnormal retracted or unlocked position. Thus when the cam 66 is rotatedin order to restore the bolt 22 to a locked position the spring 104 doesnot make contact with the formation 34.

The spring 104 is a preferred item for it enables a yielding force to beexerted by the formation 34 on the lever 36. It can however be replacedby a substantially solid unyielding element and, as before, theformation 34 will, when contacting such element, urge the lever 36 topivot downwardly. This type of construction may however createadditional stress on other components of the lock.

The arrangement of FIGS. 6 to 10 therefore enables the spring forcewhich is exerted on the arm 40 to be reduced during most of the timeinterval for which the cam 66 acts on the arm. However, at limitingpoints, the additional spring force exerted from the leaf spring 100 andthe leaf spring 104 (when this second leaf spring is used) ensures amore positive locking action of the levers 36.

FIGS. 11 to 14 illustrate a lock 210 according to a third form of theinvention from the side in different operating configurations which aredescribed hereinafter. Reference numerals used in connection with thefirst form of the invention are used to designate like components andthe following description is directed mainly to points of differencebetween the two embodiments.

A spring 250 has opposing ends fixed to the power lever 46 and an anchorpoint on the housing, respectively.

A catch 252 which has a hook formation 254 is pivotally fixed to a point256 on the bolt. A spring 258 acts between the catch 252 and thehousing.

The hook formation 254 is adjacent a spigot or similar formation 260 onthe power lever 46.

A spring 262 acts between the bolt 22 and the housing or the face plate14.

A leaf spring 264 has one end fixed to the catch 252. The opposing endof the leaf spring is free. The leaf spring however bears on a cam 266which is mounted for rotation about an axis 268. A small electric motor270 is used to rotate the motor cam.

The motor cam opposes a recessed formation 272 in upper end surfaces ofthe arms 40 of the levers, and a triangular-shaped bolt cam formation274 on an upper side of the bolt.

A micro-controller 276 which includes a receiver and decoder unit ismounted inside the housing. This unit draws power from a battery 278which is shown mounted inside the housing.

The micro-controller 276 and the battery 278 may, according torequirement, be mounted in an enclosure (not shown) which is separatefrom the housing 12 and which is relatively easily accessible.

FIG. 11 illustrates the lock in a position with the bolt 22 extendingfrom the housing. If the lock is installed in a door then clearly thebolt 22, in the illustrated position, is engageable with a striker plateon a door frame in order to keep the door in a closed and lockedposition.

If the lock is to be operated electronically then a user presses anunlock button on a remote control device such as a radio transmitter.Again it is to be noted that the use of a radio transmitter, forcontrolling the operation of the lock, is given merely by way of exampleand that any suitable remote or non-contact method, eg. a keypad,magnetic card or similar device, can be used for actuating the lock. Anactuator of this type may more generally be referred to as an electronickey. The electronic key ideally has the facility for making use of acoded signal which is decoded by the unit 276 to enable locking andunlocking operations to take place. If an incorrectly encoded signal isreceived then the lock will not be operated. Clearly this is a securityfeature.

If the receiver recognises a transmitted code then the motor 270 isdriven with power drawn, for this purpose, from the battery 278. Themotor acts on the cam 266 through a gear box or similar leverarrangement and turns the cam through 90°.

As the motor cam rotates it bears downwardly on the arms 40 of thelevers which are then moved to the FIG. 12 position at which the boltcatch 34 is centrally positioned in the shaped apertures 38. This makesit possible for the bolt to be moved from the locked position shown inFIG. 11.

The motor cam also bears on the leaf spring 264. The leaf spring isextended upwardly and the catch 252 is thereby urged downwardly,pivoting about the point 256 and, at the same time, acting against thespring 258. The catch formation 254 is thus moved to a position at whichit can engage with the spigot 260 on the power lever.

If one of the handles 20 is now pushed downwardly then the cam 16 causesthe power lever 46 to pivot about the pivot point 48 in the direction ofan arrow 280, see FIG. 11. The spigot 260 is rotated together with thelower end of the power lever, and pulls the power lever to the right inFIG. 11, thereby moving the bolt to an unlocked position at which thebolt is fully retracted into the housing. In this form of the inventionthe bolt is guided in this movement by the pin 28 which is located inthe elongate slot 26. It is to be understood though that any other guidedevice may be used in place of the pin 28.

As the bolt is retracted into the housing the bolt spring 262 isextended and energy is thereby stored in the spring.

Initially the motor cam 266 is engaged with the recessed formation 272in the lever arms 40.

However as the bolt slides into the housing the bolt cam formation 274causes the motor cam 266 to rotate in an anti-clockwise direction. Thisallows the spring 42 to act on the levers 36 and pivot the levers in aclockwise direction so that the bolt catch 34 is again moved intoengagement with the shaped apertures 38, as is shown in FIG. 13. Despitethe restoring action of the spring 262, which is extended, the boltcannot move to the left, relatively to the housing, for the bolt catch34 prevents this movement.

The power lever 46, which is acted on by the spring 250, which is nowextended, attempts to rotate in a clockwise direction about the pivotpoint 48. It is however prevented from rotating for the spigot 260 isengaged with the hook formation 54 and is kept engaged in this way whilethe handle 20 is fully depressed.

When the handle is released it rotates upwardly under the action of aninternal spring, not shown. The cam 16 then no longer prevents the powerlever 46 from being rotated by the spring 250 and the spigot 260 isconsequently moved out of engagement with the catch formation 254. Thespring 258 then acts on the power lever catch 252 which is pivotedupwardly.

If the handle is rotated fully a pin or stop formation acts on the cam16 to prevent excessive rotation of the handle. This prevents excessiveforce being exerted by the catch 34 on inner sides of the apertures 38.

The lock is now in an opened position as shown in FIG. 14.

The bolt may be moved to the locked position, shown in FIG. 11, in twoways.

In the first instance a key may be inserted into the keyhole 44 androtated in a conventional manner, which is known in the art. The keyacts on the levers 36 and urges the levers upwardly so that the shapedapertures 38 are moved out of engagement with the bolt catch 34,substantially as is shown in FIG. 12. Further rotation of the key bringsthe key into engagement with the recessed formation 32 in the bolt andthe bolt is moved to the left, relatively to the housing, to the lockedposition.

The lock may also be actuated electrically, again by making use of thetransmitter already referred to. The user presses a lock button on theremote control device, or electronic key, and if the receiver anddecoder unit 26 recognises the transmitted code the door lockingmechanism verifies that the door is closed. If the door is closed themotor cam 266 is rotated through 90° by means of the motor 270. Themotor cam 266 acts on the lever arms 40 which are thereby pivoted aboutthe pivot pin 28 in precisely the same way as occurs when the key actson the lock levers.

The motor cam 266 lifts the lock levers out of engagement with the boltcatch 34 which is then positioned centrally in the shaped apertures 38.The spring 262 can then urge the bolt to the left, to the lockedposition. As the bolt slides out of the housing the bolt cam formation274 releases the motor cam and the system is thereby returned to theconfiguration shown in FIG. 11 with the bolt catch 34 again engaged withthe shaped apertures 38.

The cam 266 has been described as being movable under the action of anelectric motor 270. This is not essential for the cam can be moved usingany other suitable actuator such as a solenoid. As is the case with theembodiments already described, an important aspect of the inventionhowever lies in the fact that the cam acts only to move the retainingmeans which is engaged with the bolt, and does not move the bolt itself.The bolt is manually moved by a user from the locked to the unlockedposition and, at the same time, energy is accumulated in the spring 262which energy is subsequently available, when required, in order to movethe bolt from the unlocked to the locked position.

FIG. 15 shows a modified lock 310 according to the invention wherein thelever 46 is replaced by a lever 346 which is pivotally connected to acam 16A at a pivot point 300.

The springs 250 and 258 of FIG. 11 are dispensed with. A leaf spring 364is fixed to a catch 352 and bears against a stop 402.

In other respects the lock 310 is similar to the lock 210 and operatesin a similar way, but is of a simplified construction.

FIG. 16 schematically depicts electronic components which are used tocontrol the operation of the lock of FIG. 11 and to provide an interfacebetween the lock and a user. It is apparent however from the ensuingdescription that the two embodiments of the lock can be controlled in asimilar way.

The block diagram of FIG. 16 illustrates the main electronic componentsrequired for lock operation. These components include themicro-controller 276, a radio frequency receiver circuit 420, thebattery 278 which is used to power the electronic components, a driver422 for the electric motor 270, two green LED's 424 and 426respectively, a red LED 428, a buzzer 430, a press button 432 andsensors 434, 436, 438 and 440 which respectively are used for sensingthe position of the motor 270, the cam 266, the catch of the lock (if acatch is used), and the bolt 22.

The movement of the motor 270 is controlled by the micro-controller 276and the sensors 434 and 436 are used in a feedback mode to giveinformation on the position of the cam 266 and to control the movementof the cam through the required angle.

Alternatively use is made of a mechanical stop and the motor is operatedfor a predetermined period of time which is more than sufficient tobring the cam into engagement with the stop. This controls the positionof the cam.

An overload sensor could also be used to monitor the current drawn bythe motor to determine when the cam is in contact with the stop, andthen to interrupt the power supplied to the motor.

The micro-controller controls the operation of the buzzer 430 and theoperation of the LED's 424 to 428. The components 424 to 430 are used asan interface 442 between the lock and a user and provide statusinformation on the lock to a user. As has been noted the lock may beremotely operable from diverse sources, including signals transmitted byradio transmitters. These signals are received by the receiver 420 andthey are used to place the lock into a locked or unlocked mode.

The sensor 440 is used to detect whether the bolt is in a locked orunlocked position. The sensor is also capable of detecting whether auser has used a key to lock or unlock the bolt. The function of a sensor444 is to ensure that the bolt 222 can only be released or moved to alocked position when the door is closed.

The interface 442 is used, as has been indicated, to provide statusinformation on the lock to a user.

The two green LED's 424 and 426 are connected in parallel. The LED 424is mounted so that it may be seen from an outer side of the door towhich the lock is attached while the LED 426 is visible from theinterior side of the door. The red LED 428 is mounted so that it can beseen only from the interior side of the door. The buzzer 430 is mountedso that it can be heard from each side of the door.

If the lock is placed into an unlocked mode the green LED's areenergized for a few seconds indicate that the lock has been successfullyplaced into the unlocked mode and the buzzer 430 gives a short buzz toprovide an audio indication of the successful operation of the lock. Thetwo green LED's and the buzzer are then switched off.

If the lock is placed into a locked mode then the red. LED 428 flashesrapidly for a brief period to indicate that the lock has beensuccessfully placed into the locked mode and the buzzer 430 generates along buzz. Thereafter the buzzer switches off but the red LED flashesperiodically to provide a continuous indication that the lock is in alocked mode.

The detection of any user errors or internal errors is indicated bymeans of the buzzer and a specific combination of LED flashes.

The press button 432 is mounted on the interior side of the lock. Thisbutton is used for the manual locking or unlocking of the lock, or toplace the lock into a “learn” mode so that a new transmitter code may belearnt by the lock i.e. stored in the lock.

FIG. 17 illustrates a lock 500 according to a different form of theinvention wherein a solenoid is employed in place of a motor.

The following description is essentially directed to points ofdifference in the construction of the lock.

A cam 588 has an extension piece 502 and a link 504 is pivotallyconnected to the extension piece and to a bolt 592.

The link 504 is not permanently engaged with the bolt 592. When thelevers 596 move upwardly, the levers 596 press the link 504 onto thebolt 592, engaging the link 504 with the bolt 592. If the handle is nowoperated, a force is applied to the bolt 592 via the link 504. When thelevers 596 are released, and return to the initial position shown inFIG. 17, the levers 596 release the link 504 and the link 504 thendisengages from the bolt 592. If the handle is now operated, the link504 moves freely, without exerting force on the bolt 592.

A member 506 extends from the levers 596 to one side of the guide pin530.

A solenoid 508 is fixed to the housing 598. The solenoid has a rod 510which extends from a housing 511 of the solenoid and an upper end of therod is attached at a point 512 to the member 506. The member carries apin 514 which is engaged with a shaped channel 516 formed in a complexcam 518 which is shown in enlarged detail in FIG. 18.

The cam is mounted on an upper end of a limb 520 which includes fixingformations 522 whereby the cam is secured to the housing 511 of thesolenoid. Alternatively the cam could be fixed to the housing 598. Thelimb is formed with recesses 524 which define a zone of weakness in thelimb.

As has been noted, the pin 514 is located in the channel 516. Thechannel has a complex shape and is designed to cause movement of thepin, and hence of the member 506 and the levers 596, in a predeterminedmanner.

A projection 526 extends from an upper end of the cam 518. A protrudingrod 528, see FIG. 17, extends laterally from the bolt 592 and ispositioned so that if the bolt is slid, to and fro, the rod strikes theprojection 526.

The solenoid 508 replaces the motor 270 shown in FIG. 11. When thesolenoid is energized the rod 510 is retracted and the member 506 ispivoted downwardly, moving about a guide pin 530. The levers 596 thenmove upwardly and apertures 538 are thus displaced, relatively to a stopformation 534, to a position at which the bolt can be moved with asliding action. The pin 514, which is carried on the member 506, isthereby caused to move within the channel 516. Although the limb 520 isessentially rigid the zone of weakness which is formed by the formations524 enables the limb to flex so that the pin Is able to move inside thechannel in a guided and controlled manner.

The rod 528, which is carried by the bolt 592, is positioned so that,upon movement of the bolt, it strikes the projection 526 and therebydeflects the cam to one side, as the limb flexes about the zone ofweakness.

FIG. 18 illustrates four possible paths, designated M, N, O and Prespectively, which the pin 514 can take when travelling inside thechannel 516.

FIG. 19 is a flow chart representation of various steps when unlockingthe lock 500 which initially is in a locked state 540.

As has previously been explained a validation procedure 542 is carriedout when a remotely transmitted signal is received by the lock. If avalid codeword is not received, or if no codeword is received, then anLED is caused to flash (step 544). If a valid codeword is received thenin a step 546 the solenoid 508 is activated and the rod 510 is drawndownwardly. The pin 514 moves to position C, see FIG. 18, travellingalong the path M. As has been stated this movement is allowed for inthat the limb 520 can flex about its zone of weakness. The member 506 isalso drawn downwards, and the levers 596 are displaced upwardly topositions at which the sliding movement of the bolt is no longerprevented by the engagement of the formation 534 with the apertures 538.

When the solenoid is deactivated, the pin 514 continues to travel alongpath M to position B.

The lock stays in this position indefinitely with further opening actiononly taking place if the handle, which works on the cam 588, isoperated. When this occurs the bolt is slid to the right in FIG. 17, byvirtue of the link 504 which connects the bolt to the cam, and the pin514 moves from position B to position A. As the bolt moves to the rightthe rod 528 acts on the projection 526 and causes the limb 520 to flexso that the pin 514 is able to move inside the channel 516 to return tothe position A, via the path N (step 548). The lock is then in anunlocked mode 550.

When the bolt is moved to the unlocked position energy is stored in aspring of any appropriate kind. In this instance a spring 552 ispositioned between an end surface of the bolt and an opposing surface ofthe housing. The spring is held in the compressed state for the stopformation 534 is engaged with the apertures 538 in the lever and thebolt cannot therefore return to the extended position.

With the lock at position B, and if the handle has not been operated buta remote signal is received by the lock, then if a valid codeword isidentified in a validation procedure 554 the solenoid 508 is againenergized in a step 556. The bolt 592 is in the position shown in FIG.17 as the handle has not been operated. When the solenoid is energizedthe rod 510 is drawn downwardly, pivoting the member 506, and the pin514 therefore travels from the position B further downwardly into thecam and then returns to the position A via the path O. The lock istherefore restored to the fully locked position 540.

FIG. 20 illustrates the operations which are carried out when the lock500 is returned from an unlocked mode 550 to a locked mode 540. Aremotely transmitted signal is again subjected to a validation procedure558 and if a valid codeword is identified the solenoid is energized in astep 560.

The pin 514 is thereby caused to travel along the path P to the positionB. The member 506 pivots downwardly while the levers 596 move upwardly.The stop formation 534 is thus released from the apertures 538 and thespring 552 extends forcing the bolt to the left relatively to thehousing 598. It is to be borne in mind that this movement is effectedmaking use of stored energy previously generated by the user in openingthe lock.

As the bolt moves to the left the protruding rod 528 strikes theprojection 526. Thus the cam 518 is also moved to the left, flexingabout the zone of weakness in the limb 520. The pin 514 thereforereturns, in a step 562, to the position A moving along the path P. Thelock is thereby restored to the locked mode 540.

The interaction of the pin 514 with the complex channel 516 isequivalent to that of an indexing system which enables the position ofthe bolt to be controlled in a precise manner. The solenoid is used in away which is similar to that in which the motor 570 is used in that thesolenoid provides the force which is used to release a retainingmechanism which prevents movement of the bolt. The movement of the bolton the other hand is done manually using energy generated by a user. Inmoving the bolt from a locked to an unlocked mode sufficient energy isstored to enable the bolt, once it has been released by the retainingmechanism, to be restored to the locked mode.

What is claimed is:
 1. A lock comprising: a bolt which is movablebetween a locked position and an unlocked position; first retainingmeans for, at a first position, engaging said bolt and retaining saidbolt in the locked position; remotely actuable release means for movingsaid first retaining means from the first position to a second positionout of engagement with said bolt; an energy storage device that powerssaid remotely actuable release means; handle means for moving said boltfrom the locked position to the unlocked position when said firstretaining means is disengaged from said bolt; energy storage means foraccumulating energy as said bolt is moved to the unlocked position;second retaining means, engageable with said bolt, for retaining saidbolt in the unlocked position; and means for disengaging said secondretaining means from said bolt whereupon said energy storage meanscauses said bolt to be moved to the locked position.
 2. The lockaccording to claim 1 wherein said remotely actuable release means iselectrically actuable in response to an externally generated signal. 3.The lock according to claim 2, further comprising at least one of a cardreader, keypad, a recognition device, a switch device, and a radiotransmitter, for producing the externally generated signal.
 4. The lockaccording to claim 2, wherein said remotely actuable release means isresponsive to a signal which is output by a receiver and decoder unitwhich, in turn, is responsive to an externally generated signal.
 5. Thelock according to claim 1, wherein said first and second retaining meanscomprise interengageable formations respectively on said bolt and on atleast one lever.
 6. The lock according to claim 1, further comprising acam, a gear mechanism which acts on said cam, and an electrical motorthat drives said gear mechanism, and hence said cam, in a controlledmanner, for moving said first retaining means.
 7. The lock according toclaim 1, further comprising a key for moving said first and secondretaining means.
 8. The lock according to claim 1, further comprising areceiver that receives externally generated signals and wherein, uponreceipt of one of the externally generated signals that is correctlyencoded, said first and second retaining means are caused to move. 9.The lock according to claim 1, further comprising a cam that acts onsaid first and second retaining means, an electrically driven gearmechanism which is remotely controllable for causing controlled movementof said first retaining means from the first position to the secondposition and of said second retaining means into engagement with saidbolt, said second retaining means then restraining said bolt from beingmoved from the unlocked position to the locked position, and means forpreventing movement of said cam in at least one direction when said boltis moved to the unlocked position.
 10. The lock according to claim 9,wherein said energy storage means is also for providing energy forrestoring said bolt to the locked position.
 11. The lock according toclaim 9, wherein said energy storage means is also for accumulatingenergy as said bolt is moved to the locked position and for providingenergy for restoring said bolt to the unlocked position.
 12. The lockaccording to claim 9, wherein said electrically driven gear mechanismcomprises an electric motor that drives a gear arrangement and isresponsive to an externally generated signal for causing operation ofsaid electrically driven gear mechanism.
 13. The lock according to claim12, wherein said electric motor is responsive to a signal which isoutput by a receiver and decoder unit which, in turn, is responsive tothe externally generated signal.
 14. The lock according to claim 13,wherein the externally generated signal is generated by an electronickey.
 15. The lock according to claim 1, wherein said bolt comprises astop formation and said first retaining means comprises at least onelever that is engageable with said stop formation.
 16. The lockaccording to claim 15, wherein said at least one lever is movablemanually by means of a key into engagement with said stop formation. 17.The lock according to claim 1, further comprising sensor means fordetecting whether a door, to which the lock is fitted, is open or closedand for allowing actuation of said bolt in a manner which depends on aposition of the door.
 18. The lock according to claim 1, furthercomprising a catch which is movable, by said handle means, from alatched to an unlatched position.
 19. The lock according to claim 1,further comprising a device which is movable between a first position atwhich, upon operation of said handle means, said bolt is caused to moveto the unlocked position, and a second position at which upon operationof said handle means, no movement of said bolt results.
 20. The lockaccording to claim 19, wherein said device is selected from a spring anda catch.
 21. The lock according to claim 19, wherein said device ismovable by said first retaining means.
 22. A method of operating a lockthat includes a bolt, a catch and a handle, the method comprising thesteps of: causing the bolt to move from a locked position to an unlockedposition when the catch is moved by means of the handle from a latchedposition to an unlatched position; storing energy when the bolt is movedfrom the locked position to the unlocked position; latching the bolt atthe unlocked position using a retainer; with the bolt at the unlockedposition allowing the handle to act on the catch independently of thebolt; transmitting a signal to actuate the retainer to unlatch the bolt;and allowing the bolt to move from the unlocked position to the lockedposition, under the action of the stored energy independently of thecatch.
 23. The method according to claim 22, wherein the transmittedsignal is generated using an electronic key.
 24. A lock comprising: abolt which is movable between a locked position and an unlockedposition; first retaining means for engaging said bolt to retain saidbolt in the locked position; remotely actuable release means for movingsaid first retaining means out of engagement with said bolt; handlemeans for moving said bolt from the locked position to the unlockedposition when said first retaining means is disengaged from said bolt;and a catch which is movable, by said handle means, from a latched to anunlatched position.
 25. The lock according to claim 24, furthercomprising second retaining means for moving in response to saidremotely actuable release means to a position at which said secondretaining means restrains said bolt from being moved from the unlockedposition to the locked position.
 26. The lock according to claim 24,further comprising energy storing means for accumulating energy whensaid bolt is moved to the unlocked position and for providing energy forrestoring said bolt to the locked position.
 27. The lock according toclaim 24, wherein said remotely actuable release means is electricallyactuable in response to an externally generated signal.
 28. The lockaccording to claim 27, further comprising one of a card reader, keypad,a recognition device, a switch device, and a radio transmitter forproducing the externally generated signal.
 29. The lock according toclaim 24, wherein said remotely actuable release means is responsive toa signal which is output by a receiver and decoder unit which, in turn,is responsive to an externally generated signal.
 30. The lock accordingto claim 25, wherein said first and second retaining means are comprisedof interengageable formations on said bolt and on at least one leverrespectively.
 31. The lock according to claim 24, further comprising acam, a gear mechanism which acts on said cam, and an electrical motorthat drives said gear mechanism, and hence said cam, in a controlledmanner for moving said first retaining means.
 32. The lock according toclaim 25, wherein said first and the second retaining means are movableby a key.
 33. The lock according to claim 25, further comprising areceiver that receives externally generated signals and wherein, whenthe externally generated signal is correctly encoded, said first andsecond retaining means are caused to move.
 34. The lock according toclaim 24, further comprising an energy storage device for powering saidremotely actuable release means.
 35. The lock according to claim 24,further comprising a cam that acts on said first retaining means, anelectrically driven gear mechanism, which is remotely controllable, forcausing controlled movement of said first retaining means, energystorage means for accumulating energy as said bolt is moved, and meansfor preventing movement of said cam at least in one direction when saidbolt is moved to the unlocked position.
 36. The lock according to claim35, wherein said energy storage means accumulates energy as said bolt ismoved to the unlocked position and provides energy for restoring saidbolt to the locked position.
 37. The lock according to claim 35, whereinsaid energy storage means accumulates energy as said bolt is moved tothe locked position and the energy storage means provides energy forrestoring said bolt to the unlocked position.
 38. The lock according toclaim 35, wherein said electrically driven gear mechanism includes anelectric motor that drives a gear arrangement and which is responsive toan externally generated signal for causing operation of saidelectrically driven gear mechanism.
 39. The lock according to claim 38,wherein said electric motor is responsive to a signal which is output bya receiver and decoder unit which, in turn, is responsive to theexternally generated signal.
 40. The lock according to claim 39, whereinthe externally generated signal is generated by an electronic key. 41.The lock according to claim 24, wherein said bolt comprises a stopformation and said first retaining means includes a lever which isengageable with said stop formation.
 42. The lock according to claim 41,wherein said lever is movable manually by means of a key into engagementwith said stop formation.
 43. The lock according to claim 24, furthercomprising sensor means for detecting whether a door, to which the lockis fitted, is open or closed and to allow actuation of said bolt in amanner which depends on a position of the door.
 44. The lock accordingto claim 24 wherein said bolt is movable in response to operation of akey and wherein said bolt includes means for disabling operation of thekey.
 45. A lock comprising: a bolt that is movable between a lockedposition and an unlocked position; first retaining means for engagingsaid bolt to retain said bolt in the locked position; remotely actuablerelease means for moving said first retaining means out of engagementwith said bolt; handle means for moving said bolt from the lockedposition to the unlocked position when said first retaining means isdisengaged from said bolt; and a device that is movable between a firstposition at which, upon operation of said handle means, said bolt iscaused to move to the unlocked position, and a second position at which,upon operation of said handle means, no movement of said bolt results.46. The lock according to claim 45, further comprising second retainingmeans for moving in response to said remotely actuable release means toa position at which said second retaining means restrains said bolt frombeing moved from the unlocked position to the locked position.
 47. Thelock according to claim 45, further comprising energy storage means foraccumulating energy when said bolt is moved to the unlocked position andproviding energy for restoring said bolt to the locked position.
 48. Thelock according to claim 45, wherein said remotely actuable release meansis electrically actuable in response to an externally generated signal.49. The lock according to claim 48, wherein the externally generatedsignal is produced by a card reader, keypad, a recognition device, aswitch device, or a radio transmitter.
 50. The lock according to claim45, wherein said remotely actuable release means is responsive to asignal which is output by a receiver and decoder unit which, in turn, isresponsive to an externally generated signal.
 51. The lock according toclaim 46, wherein said first and second retaining means are comprised ofinterengageable formations respectively on said bolt and on at least onelever.
 52. The lock according to claim 45, wherein said first retainingmeans is movable by means of a cam, a gear mechanism which acts on thecam, and an electrical motor which drives the gear mechanism, and hencethe cam, in a controlled manner.
 53. The lock according to claim 46,wherein said first and the second retaining means are movable by a key.54. The lock according to claim 46, further comprising a receiver thatreceives an externally generated signal and wherein, upon receipt of acorrectly encoded signal by said receiver, said first and secondretaining means are caused to move.
 55. The lock according to claim 45,wherein said bolt is movable in response to operation of a key andcomprises means for disabling operation of the key.
 56. The lockaccording to claim 1, wherein said bolt is movable in response tooperation of a key and comprisese means for disabling operation of thekey.